Chapter 4 - Cell Structure

Question 1

ribosomes (function, composition, and where found)

Answer 1

• Function: The cell’s protein synthesis “machinery”.
• Composition: Ribosomal RNA (rRNA) and proteins
• Found: on rough ER, in the cytoplasm, and associated with membranes

Question 2

plasma membrane

Answer 2

A phospholipid bilayer that separates a cell from its surroundings. (Embedded proteins allow it to interact with its surroundings.)

Question 3

Mathias Schleiden & Theodor Schwann

Answer 3

Proposed the Cell Theory in 1839

Question 4

Robert Hooke

Answer 4

Discovered the cell in 1665 through a cross-section of a cork.

Question 5

Cell Theory (as proposed by Schleiden and Schwann in 1839)

Answer 5

1. All organisms are composed of cells.
2. Cells are the smallest living things.
3. Cells arise only from pre-existing cells.
   (All cells today represent a continuous line of descent from the first living cells.)

Question 6

nucleus

Answer 6

• stores the genetic material of the cell in the form of multiple, linear chromosomes
• surrounded by a nuclear envelope composed of 2 phospholipid bilayers

Question 7

mitochondrion

Answer 7

• The “power house” of the cell - generates ATP.
• Contains its own DNA.
• -surrounded by 2 membranes:
  
  • smooth outer membrane
  • folded inner membrane with layers (called cristae)

Question 8

lysosome

Answer 8

• The “trash can” of the cell.
• membrane bound vesicles containing digestive enzymes to break down macromolecules
• destroy cells or foreign matter that the cell has engulfed (by phagocytosis)

Question 9

Golgi apparatus

Answer 9

• The “shipping and receiving” department of the cell.
• flattened stacks of interconnected membranes
• packaging and distribution of materials to different parts of the cell
• synthesis of cell wall components

Question 10

endoplasmic reticulum (generic function and composition)

Answer 10

• Functions: Synthesize proteins and fats, detoxify foreign substances, store calcium
• Composition: phospholipid bilayer embedded with proteins

Question 11

chromosome

Answer 11

Linear structures in the nucleus that store the genetic material of the cell.

Question 12

chromatin

Answer 12

In chromosomes – DNA organized with proteins.

Question 13

Discovered the cell in 1665

Answer 13

Robert Hooke

Question 14

Proposed the Cell Theory in 1839

Answer 14

Mathias Schleiden & Theodor Schwann

Question 15

The cell’s protein synthesis “machinery”.

Answer 15

Ribosomes

Question 16

Cell Theory: All cells have certain structures in common

Answer 16

1. genetic material – in a nucleoid or nucleus
2. cytoplasm – a semifluid matrix
3. plasma membrane – a phospholipid bilayer

Question 17

A phospholipid bilayer that separates a cell from its surroundings. (Embedded proteins allow it to interact with its surroundings.)

Answer 17

Plasma membrane

Question 18

• stores the genetic material of the cell in the form of multiple, linear chromosomes
• surrounded by a nuclear envelope composed of 2 phospholipid bilayers

Answer 18

Nucleus

Question 19

The “power house” of the cell - generates ATP.

Answer 19

Mitochondrion

Question 20

The “trash can” of the cell.

Answer 20

Lysosome

Question 21

The “shipping and receiving” department of the cell.

Answer 21

Golgi apparatus

Question 22

Synthesizes proteins and fats, detoxifies foreign substances, stores calcium

Answer 22

Endoplasmic reticulum

Question 23

Rough endoplasmic reticulum (why “rough”, function)

Answer 23

• “Rough” due to embedded ribosomes in the membranes.

* Function: synthesis of proteins to be secreted, sent to lysosomes or plasma membrane.

Question 24

Smooth endoplasmic reticulum (why “smooth”, function)

Answer 24

• “Smooth” due to few embedded ribosomes in the membranes.
• Functions:
  
  • synthesis of membrane lipids
  • calcium storage
  • detoxification of foreign substances

Question 25

Linear structures in the nucleus that store the genetic material of the cell.

Answer 25

Chromosome

Question 26

In chromosomes – DNA organized with proteins.

Answer 26

Chromatin

Question 27

Centriole

Answer 27

Barrel-shaped organelles found in the cells of animals and most protists, near the nuclear membrane. (Lacking in plants.)

Question 28

Centrosome

Answer 28

• Microtubule-organizing centers.

* Responsible for the reorganization of microtubules that occurs during cell division.

Question 29

Centromere

Answer 29

The point of constriction on the chromosome containing repeated DNA sequences that bind specific proteins.

Question 30

Chromatid

Answer 30

One of two (sister) replicated chromosome strands, held together at their centromeres by cohesion proteins after replication.

Question 31

The point of constriction on the chromosome containing repeated DNA sequences that bind specific proteins.

Answer 31

Centromere

Question 32

One of two (sister) replicated chromosome strands, held together at their centromeres by cohesion proteins after replication.

Answer 32

Chromatid

Question 33

Microtubule-organizing centers.

Answer 33

Centrosome

Question 34

Barrel-shaped organelles found in the cells of animals and most protists, near the nuclear membrane.

Answer 34

Centriole